To do this in a single Time Machine, the "tricky" part is that you want to ping pong loop only a part of your retimed result at the end. Typically the looping capabilities of Time Machine apply to the Target Frame Range, i.e. the entire bit where the retiming happens.

So what you could do, for example, is use two Time Machines. One to do the 30 frame offset at the start, and another to do the ping pong loop at the end.

I've made a quick example of how that could work. I've taken frame 1 as the first frame and worked with your values divided by 10 to keep the resulting numbers a bit more convenient for educational purposes

While it can be done this way, it does require too much fiddling with numbers to my taste, and it's really very error-prone and counter-intuitive. I would not want to build a setup with a dozen of these, all with different values. And the nightmare only continues when you want to change your timing.

But there's a much better and easier way to do this. Enter XSheet mode. Do read the post that I just linked to.

So with Xsheet mode, you can do what you are after with these two lines only:

Line 1 transates to "hold frame 1 for 30 frames, then continue to 130" while line 2 takes care of your loop: "count from 129 to 100 then back to 130 and loop that 10 times". You can loop it 10000 times to get closer to "forever"

If you wanted to spit it up further for clarity, you could split that first line this way as well to do the same thing:

Thank you so much for your help, after looking at your example I finally got an understanding of how xsheet works and how simple it is to make a ping-pong expression.
Its now so much simpler to control and adjust all my blooms timings in the project....

The time machine node is extremely powerful, amazing work!

I hate making tutorials, but it might help someone else having the same question:

I am a bit confused about using the trigger mode in combination with either an audio file or a MIDI-file.
When using a midi-file I'd like to use ONLY the NOTE-ON effectively. So if a note lasts two beats, I only want to use the part when the note is played for the first time.
I think the trigger option in Time Machine should do what I need, but I don't know how to set it.
For example I have a note that plays from frame 15-18. I want to trigger an event/value only on frame 15. But since the note is constant for 15-18 I don't know how to set the trigger treshold values, since there's no decay in the data. Any suggestions on how to either set the MIDI extractor to use only the NOTE-ON or how to set the Time Machine Fuse to do this for me will be greatly appreciated.

Think of the Text+ node as your event/value. That's what you want as a result whenever your Midi file produces a NOTE-ON. Your Trigger is the Midi file itself, so that's where I animated a couple of keyframes to simulate that.

As long as nothing happens, Text+ will stay at frame 0 (the Source Start Frame). As soon as the value in the Trigger goes higher than the On Trigger Threshold, the Text+ starts playing back at the Run Speed. This happens on frame 15, where we get frame 1 in the sequence, and 2, 3 and so on for the frames after that. This until the Trigger value goes below the Off Trigger Threshold, at which point the image sequence does whatever the Trigger Mode is set to. In this case that is Reset, so it will jump back to frame 0.

In your case, we only really care about the On Trigger Threshold. The one thing to take away from our example is that you want your event to be at frame 1 of your source, not at frame 0 (what you may assume intuitively).

So knowing this, here's an example on how to do it with input (parameter) values. In this next example, we'll create a BG node and animate our event (a single red frame) on frame 1:

With that done, we have our source "image sequence" and next we need to insert a Time Machine modifier:

This way, we basically have the same setup as our Text+ example, but with numbers instead: Animation Spline -> Time Machine -> Red Channel.

In this case we are not interested in frame numbers, like when we work with image sequences (when we want to know which frame we need for our re-time). Instead, we want the values assigned to those frame numbers, i.e. our "event" that we just animated. So we set our Output Type to Value at Frame:

Notice that when we do that, we get an extra Value Input control, which is our animation on our Background's Red Channel.

With our Mode set to Trigger, all we need to do is modify the Trigger itself with whatever we want our need, in your case that will be a MIDI Extractor I imagine. Set your On Trigger Threshold to an appropriate value and you should be all set!

There are simple thing that Trigger doesn't do, like why can't it simply return a single value when a trigger happens? Again, when I needed this functionality I was re-timing image sequences and 3D scenes and that didn't make much sense in that context. Once you start thinking of TM as a tool to adjust parameters with, there are many things like that I'd want to add straight away.

@SecondMan I'm trying to use Timemachine on a longer comp (4700 frames) and I'm using a Wav modifier to trigger my timemachine to start/restart a 15 frame loop. I have the feeling that this is much quicker for the first 100 frames than it is for somewhere in the middle/end. Do you think this could be because of the WAV modifier or the timemachine?

That would be expected and it's from Time Machine. Trigger is one of those modes that goes over the entire valid timeline range up to the current time. I'm sure there are ways to make that faster, but I'm afraid that's a little further down on the to-do list right now... It should still be reasonable though.